Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 cda6fb227dc18e95…

MALICIOUS

Office (OLE) / .XLS

76.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: eb60a164837df2fb804253183af58f51 SHA-1: 39b106e2521b4c9915aa7b0b379c8c2ab269438e SHA-256: cda6fb227dc18e95dc69a0b18c0135c2c1be285fff72d9a4173bd058a75ea19e
120 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute. It presents a lure impersonating DocuSign to encourage users to enable macros. The macro sheet contains references to `rundll32`, `DllRegisterServer`, `uRlMon`, and `RLDownloadToFileA`, indicating an attempt to download and execute a payload from one of the listed URLs. The presence of these functions and the lure strongly suggest a downloader or droppper functionality.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
28583d80fd380b8ce44feed33486a243b72383f3879b4322afeadd5f9732c23b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2255 bytes